Rock-drilling machine



J. D. PRITCHARD :TAL 2,913,226

ROCK-DRILLINGV MACHINE Nov. 17, 1959 Filed sept. 29. 1952- l 4 Sheets-Sheet 1 FIGA,

' #warf/sys.

Nov. 17, 1959 J. D. PRICHARD LErm.

ROCK-DRILLING MACHINE 4 Sheets-Sheet 2 Filed Sept. 29, 1952 Nov. 17, 1959 J. D. PRn'cHARD E-rAL 2,913,226

ROCK-DRILLING MACHINE Filed Sept. 29, 1952 iwf/frogs, Jac/170mm P19/mmm mmm/Fys.

New 17, 1959 JD. PRITCHARD :TAL y ROCK-DRILLING MACHINE 4 sheets-sheer 4 Filed Sept. 29. 1952 United States Patent O ROCK-DRILLING MACHINE Jack D. Pritchard, Kirkwood, Mo., and Stephen Roy Blackwell, East St. Louis, Ill- Application September 29, 1952, Serial No. '312,134

z claims. (ci. ass-s1) This invention relates to rock-drilling machines for use in quarrying and mining operations, particularly subsurface operations.

It will be understood a common method of breaking up the rock fron-t or face is by blasting, and modern techniques have led to the use of sequentially tired charges of explosives placed in the face according to a carefully selected pattern. For example, in one such pattern the blasting holes are arranged in horizontallyspaced inwardly-convergent vertical rows. The two innermost rows are tired first and the remaining rows are fired successively in the direction away from the middle, with 'the result being a spreading collapse of the face. Experience has shown the accuracy in the pattern of the blasting holes is important to the successful carrying out of such blasting.-

Heretofore, such drilling has been carried out from portable scaffoldingplaced up against the face, but this has not been entirely satisfactory, because considerable time was wasted in moving the scaffoldingfandbecause the holes were not always in the proper degreeof alignment, depth, etc. It is accordingly an object of this invention to provide a rock-drilling machine adapted to drill a relatively wide width of the face in a relatively short time. Another object of this invention is the provision o f a rock-drilling machine for facilitating the drilling ofaccurately placed blasting holes. v

To the attainment of these objectives, weprovide a wheeled vehicle constructed with a fixed superstructure of such height as to clear the ceiling of the Vquarry or mine:

and permit the vehicle to traverse the mine floor. A pairof upright rails are slidably mounted in the superstructure onopposite sides of the machine, and these rails are 'extendable out of the superstructure for engagement with the mine ceiling. A boom carriage ridesupon the rails, and a boom is cantilevered from the carriage on a pivotal support, which permits the boom to be swung todifierent positions in a horizontal plane. At the outer end of the boom, there isa drilling unit including the usual elon-A gate motor rail, drill motor movable 'therealong and'A elongate drill bit. The unit is preferably pivoted at its center with a double hinge to permit its adjustmenttboth horizontally and vertically with respect to the boo'rn;

Inoperation, the drilling unit and boom. areadjusted and locked in position for drilling a lowermost blasting hole for one of the vertical rows of the pattern.V The carriage-supporting rails and the carriage may then be ele-l vated for drilling superimposed holes forming the remainder of the particular row. When the row is com-l AThe invention also contemplates the provision of an` elevating system wherein a winch-controlled hoisting cableisY trained about the carriage-supporting railsfsof p that lthe rails are trst elevated with the carriage resting at drill motor fully retracted;l

their bottom, untilthe frame engages the ceiling of the mine vor quarry. Further elevation is then obtained by movement of the carriage and attached boom relative to the rails, the rails remaining in contact with the ceiling to provide a stabilizing action during elevated drilling operations.

The particular cable system may vary, depending upon the relative weights of the frame and the carriage with its attached parts.

An additional feature of this invention is a provision :of anintermediate support for the elongate drill bit of the drilling unit. With the rock-drilling machine of this invention, the drilling unit per se might be quite long (18 feet), hence an intermediate support for the drill bit, which is of corresponding length, is desirable to prevent lbreaking thereof. But as the drill motor should be advanceable the full length of the unit, the intermediate support must not interfere with the movement of the motor. In this invention, the intermediate support is automatically latched to the motor and carried forward,

Aas the 'drill motor is advanced beyond mid position.

When the motor is retracted, the bit support is detached from the motor and latched in mid position on the drilling unit to provide support for the bit.

Additionally, there isan automatically operated dust .collector shield carried at the forward end of the drilling unit for cooperation with the rock face. The drill bit extends through the dust shield, and Ithe dust shield is connected by duct and hose Ito a dust collector and filter mounted on the vehicle proper. The dust collector shield 'zand forward support for the drill rod are spring biased outwardly, and are retractable by means of a catch movably mounted at the rear of the drilling unit for actuation by the drill motor. When the drillmotor is advanced preparatory to drilling, the dust collector shield is spring ybiased into engagement with ythe rock face, and when the drill motor is fuily retracted, the dust shield is retracted against its bias in order to permit repositioning of the drilling unit preparatory to drilling a new hole.

Other features of the invention will be in part apparent from and in part pointed out in the following detail Fig'. 3 is a frontviewof the machine, the boombeing l broken away;

'Fig 4 is a side elevation of the'machine, the boom vbeing broken 0E vand a front part of the machine being shown. in section on the line 4--4 of Fig. 3;

Fig. 5 is a diagrammatic view illustratingvthe cable system for elevating the drilling unit;

'Fig. A6 is a top-plan view Fig. 7 is a side elevation of Fig. 6; Fig 8 is an enlarged 8 8 of Fig. 7; E v

eFig. 9 is an enlarged vertical section taken on the line 9-9 of Fig. 7;

Fig. 10 is an enlarged section taken on the line 10-10 of Fig. 7; Y

rFig. l1 is a side elevational viewsiinilar to thatof` Fig. 7 showing how the dust-collector sleeve is advanced when the drillmotor is partially advanced;

Fig.. 12 is a side elevation similar to that of Fig. 7 showing the drill motor advanced beyond mid point, with the intermediate support for the drill rod carried forward'` A with the drillmotor;

'-frig.- 13-is ate-paran side elevationbf uw: driuunitn? vPatented Nov. 17, 1959 of the drilling unit with the p vertical section taken on the line lustrating' the manner'is'which the intermediate support for the drill rod cooperates with the drill motor as the Referring now toFig. l of the drawings, there is shown'v a= three-wheeled powered vehicle adapted to traverseV the floor of a quarry or mine. In the form shown, the vehicle has a box-type chassis 1 with rubbertired drive wheels 3 journaled -thereon at. one end, herein termedjthe front of .the machine. At lthe other or rear end ofthe machine, there is a wheel 5 carried on a pivoted fork 7, which in turn is mechanically coupled to a conventional steering wheel 9 by a conventional steering linkage (Fig. 4).- The steering wheel extends from one side ofthe vehicleand an operators platform 11 projects from thisside of the chassis beneath the steering wheel. It is=contemplated various other operating controlsy would be located atthis side of the machine` for convenient accessto an operator standing on the platform 11.

The drive for the vehicle is provided by means of chains 13- (Fig. 4) trainedl around sprockets 15 on the drive wheels 3 and sprockets 17 on a drive shaft 18. The drive shaft 18 traversesthe boxV chassis 1 and isjdriven through a diierentiall9 by means of a-chain drive 20 and an: electric motor :21. Itis contemplated electrical supply lines1(not shown) willbe provided to extend from a:tractormay be employed. Bumpers 22 are shown as v extending from the box chassis to protect the drive wheels.

Projecting/upwardly from the chassis at itsfront are two fixed guide 'membersv 23, one on eachV side'of the chassis. These guide members 23 support a movable frame 25 which may be elevated withl respect to the chassis. The movable frame-25*l includes a pair of vertical rails27, which slidably cooperate with the vertical guide members 23 and also serve as supports for a vertical` 1y movable-carriage 29. This carriage 29Y in turn carries a boom 31 which is mounted for swinging movement in a horizontalv plane at the frontof the machine. The boom is pivoted to the carriage kat one end upon a pin 33', and at itsother end, an elongate drilling unit 35 is centrally supported by hinge apparatus generally des-y thereto, one on each side of the Iassociated rail 27. The

frame'25is thus slidably supportedv within slots defined by the flanges 39. The frame 25 also includes an top cross member` 41 and a bottom cross member 43. The carriage 29,',which extends across and through the frame 25, may thus be movedalong the frame from the lower cross member. 43 to .thetop member 41;

The carriage 29 compriseslahorizontal plate or.: platen 45,arrangedsto project through the frame-.25, and vertically disposed roller-supportingplates 47 secured along the side edges o-f theplaten. RollerszSl are' supported from the plates 47 on a shaft 52 below the platen for rolling cooperation with the forward surface' oftheframe 25. Additional rollers 55 on a shaft 53are supported from the upper back portions of the, members 47 for rolling cooperationwith theV rear surfaceV ofthe frame. The carriage also includes transverse members 57ex'- tending inwardlyfrom the side plates47 on opposite sides ofthe frame. 59, which are. journaled` for rolling cooperation with theinner surface of the rails 27V of theframe 25. It

willthereby be apparent the carriage 29 is readily movable the full length offtheframe 25, the uppermost and lowermost positions of the carriage relative. to: theframedetermined byyl engagement of: upper and lower 75 (with: its bccumete.)` are; such-,as; to insure, thisginitial.

These. members 57 support inner rollers edges 48 and 49 of the roller-supporting plates 47 with the upper and lower frame members 41 and 43, respectively.

The horizontal platen 45 of the carriage projects forwardly beyond the side plates 47, and the margin 61 ythereof is curved to provide a horizontal rail upon which rollers 63 may ride. These rollers are jounnaled upon bracket members 65 carried bythe boom so that the l boom is supportedas a pivoted cantilever, which may be swung horizontally. To lock the boom in position, there is provided a boom brake including cooperatingtoothed segments 67 and 69on the carriagev 29 and boom 31, respectively. The segmentl 69 is carried by ascrew 71 threaded through the bracket members 65, and the screw may be turned by anhand wheel 73 to move the boom segment 69 into and out of locking engagement with the carriage segment 67.

The boom 31 is constructed from two box-type beams .72 connected at the rear ends by a member 74. The

- then ydownwardly for'connecting at 79 to a dust collector or lter box 81. A suction fan 83 is mounted upon thetop of the box 81 to exhaust through the box 81 and hose 75,'into the atmosphere, as at 85. Such collector boxes are a conventional item known in the art. Dust is collected at the point of drilling in a 4manner to be explained' and carried back by air suction to the box 83. The'dust is then separated from the air by collector plates within the box, and the box is emptied from time to `time through a bottom opening (not shown).

The machine may also include screw-jacks 87 mounted on `the forward bumpers 22 for stabilizing the machine, although it will be understood the machine would include conventional wheel brakes 89 for locking the machine in position. The wheels 3, including their sprockets 15 andY brakes 89, are supported from the chassis 1 at 91.

The pin and roller support of the boom 31 upon the carriage 29 permits manual movement of the boom with respect to the carriage upon release ofthe brake 67 andl 69. The elevation of the boom is power controlled. A motor-driven hoisting winch 101 is provided upon the superstructure 103 of the machine. This winch is driven from an electric motor 105 (Fig. 4) by means of a belt'drive 107, which may include a belt-tightening idlerv 109. Cables 1114 extend from the winch 101 on opposite sides of` the machine toward the front.

Each ofv these cables is first trained around a part of av double sheave 113 supported from forwardly projecting: brackets. 115 at the top of the vertical guide members23. The cable then extends downwardly at 117 and istrained about a double sheave 119 journaled on a forwardly projecting bracket 121 at the bottom ofthe frame 25; From the sheave 119, the cable is `continued upwardly at' 123 around the other part of the double sheave 113` alndV back-down at 125'to the other part of' the sheave 119. From 119, thecable is then carried upwardly at 127 and over-a single sheave 129 on a forwardly projecting bracket 151 at the top 41 of the frame. The cable isthen extended downwardly at131 and about a sheave 133. This sheave 133 is journaled in the carriage 29,.and the cable is continued upwardly at 134 and itsend is'secured at 135 at the top of theframe- 25. Fig; 5 diagrammatically illustrates this cable system.

Withthisarrangement, it will be apparent'the lift uponA thecarriage is twice that of the tension in the cable and"l the: lift upon vthe frame 25 is four times the tension in-V the. cable. Hence upon operation ofthe winch 101, the carriage-supporting frame 25 initially moves upwardly with-the carriage 29 resting on the bottom 43 thereof. Therelativeweightsof the frame-25;. and the carriage-,29

movementlof the frame'. When the frame engages the ceiling (dashed lines of Fig. 4), the carriage then begins to move upwardly within the frame. To simplify the view of Fig. 4, the carriage is shown elevated with the With the carriage elevated in the frame, an upward l0 the weight or downward reaction of the carriage and the" thrust is continuously applied to the frame by reason of parts carried thereby. It has been found this upward force of the frame upon the ceiling is suicient, in practice, to provide a proper stabilizing action for the machine while drilling operations are conducted at some elevation from the tioor. Although the system described is satisfactory, other systems might be employed. For example, the double sheaves 113 and 119 might be converted to single sheaves, and the single sheave 133 on the carriage might be eliminated with the end of the cable being attached directly to the carriage.

Referring now to Figs. 6-14, the drilling unit 35 is supported upon the outer end of the boom 31 by the double hinge system generally designated 37. This hinge system may comprise a conventional automotive wheel brake 201 secured over the end of the boom in order to provide for horizontal swinging movement. The brake 201 may be locked as by means of a threaded actuator 205, which sets the brake in the conventional manner. A transverse pipe 207 is secured to the top of the brake 201 to project therefrom. The drilling unit 35 is then centrally balanced and supported for vertical swinging movement on this pipe 207 by a split clamp 209. Bolts 211 on the clamp lock the drilling unit in position.

The drilling unit is an item known in the art with the exceptions to be noted. The unit comprises a pair of spaced channel rails 213 with chain sprockets 215 located between the respective ends of these channel members. An air-actuated impact drill motor 217 is carried upon the rails 215 so as to be movable approximately the full length thereof. An elongate drill bit 219 is operated by this motor. The motor 217 and drill bit are advanced and retracted by means of a chain 221 trained around the sprockets 215. The chain is attached to the drill motor and is driven from an air-operated advancing motor 223 mounted below the central portion of the rails 213. The advancing motor 223, when operated, thereby applies drilling pressure to the bit.

The drilling unit of this invention is particularly dis- I tinguished by the provision of an intermediate support 225 for the drill bit and by the provision of automatically operated dust-collector shield apparatus 227. As the motor is advanced beyond midposition (Fig. l2), the support is carried forward by the drill motor 217, and when the motor is retracted again past midposition, the support is automatically detached and locked in an intermediate position (Figs. 6, 7 and 1l) to provide support for the bit. With the machine of this invention, it is contemplated the drill bit may be as long as eighteen feet, hence the intermediate support is desirable. The dust-collector apparatus 227 is automatically advanced against the rock face when the drill motor is advanced preparatory to drilling and is automatically retracted, when the drill motor is fully retracted, to permit re-positioning of the unit.

The intermediate support 225 comprises a notched vertical member 229 in which the drill bit may rest. This notched member 229 is mounted upon a bit-supporting carriage 231, which is movable over the rails 213. The frame in turn is adapted to be locked in position by a U- shaped latching link 233. The link is pivoted at 234 for cooperation with stops 235 xed upon the rails. As best shown in Fig. 13, the link 233 seats in detent notches Y 6 237 formed in the stops 235. The detent cooperation is suicient to maintain the support in its intermediate position with the motor retracted, but permits the link to be carried out of the notch 237 when the motor is advanced beyond midposition.

The drill motor carries latch plates 239, which are notched at 241 for cooperation with the link 233. The motor also has forwardly projecting prongs 243 cooperable with tubular members 245 on the movable frame 231. When the motor is advanced, the prongs 243 enter the tubular members 245, and the latch plates 241 on the motor carry the link 233 out of the notches 237 on the stops 235. The motor is thus permitted to move forwardly beyond mid position.

The link is gravity latched in the notches 241 in the" latch'` plates so that the bit-supporting carriage 231 will also retract with the motor. sloped cam surfaces 247 on the stops 235 engage the link 233 and unlatch the link by lifting it clear of the notches 241 in thellatch plates. The bit support is thus detached from the motor and latched in mid position, thereby to provide support for the relatively long, otherwise unsupported, section of the drill bit extending be- Htween a forward support 250 and the drill motor.

The forward bit support 250 is carried upon the automatic dust-shield apparatus 227. The latter comprises a short cylindrical shield 251 surrounding the drill bit. The shield is preferably formed of liexible material such as rubber to t closely with the rock face. The shield 251 is supported upon, and connects with, a duct member 255, which is connected through a telescoping pipe 253 to a hose 257. The hose is then connected to that one of the box structural beams 72 of the boom 31 which is connected to the hose 75 in the vehicle. Dust generated at the point of drilling is thus carried back to the lter box 81.

A flexible sealing member 259 in the rear of the duct 255 admits the end of the drill bit 219 and permits relative movement while sealing against air leakage at this point. Both the duct 255 and the forward bit support 250 are carried upon telescoping rods 263, which slide within tubes 265. The tubes 265 are fastened to the forward end of the rails 213. Springs 267 are fastened at 269 to the rear ends of the rods 263 and at 271 to the forward ends of the rails 213, in order to bias the dust shield forwardly into engagement with the rock face. The shield is retractable by means of cables 273 attached to the rods 265 and extended rearwardly to a sliding catch 275 supported at the rear end of the rails 213. When it is desired to retract the dust shield 251 preparatory to repositioningthe drill unit, the drill motor 217 is fully retracted to engage the catch 275 and move it rearwardly. it will be understood that the motor 217 is advanced and retracted by means of the advancing motor 223, which is under control from the vehicle.

The air lines for the advancing motor 223 and the drill motor 217 are not shown, but they may be carried back to the vehicle through the other box structural beam 72, which does not form a part of the dust collecting system. The machine may carry an air compressor or the air lines may Ibe connected from the vehicle to an existing compressed-air supply in the quarry or mine.

From the foregoing description, it is apparent that those skilled in the art will understand the structure, function and mode of operation'of the invention herein disclosed, and appreciate the advantages thereof. Although one embodiment has been disclosed in detail, it is to be understood that the invention is not limited thereto, but the drawings and' description thereof are to be understood as being merely illustrative. It is realized that many modiiications and variations will present themselves to those skilled in the art without departing from the spirit of this invention or the scope thereof as set forth in the appended claims.

As the motor is retracted,

Having thus described the invention, what is claimed anddesired to be secured by Letters Patent is:

l. A rock-drilling machine comprising al wheeled vehicle, Vertical guide means mounted upon saidvehicle, an elongate frame supported by said guide means for relative vertical telescoping movement, a carriage supported by said frame for Vertical movement relative thereto, a drilling unit carried by said carriage, an elevating mechanism comprising a winch mounted on the vehicle, a sheave mounted at the top of the xed vertical guide means, a second sheave mountedat the bottom of said frame, a third sheave mounted at the top of the xed vertical guide, a fourth sheave mounted on the bottom of the frame, a fifth sheave mounted at the top of said frame, a sixth sheave mounted on said carriage, and cable means extending from the winch over the sheaves in the order named and then to the top of said frame.

2. A rockfdrilling machine of the character set forth for use in underground mines having an overhead ceiling, Said machine comprising a wheeled vehicle, vertical guide means fixed upon said vehicle, an elongate vertical frame supported on said guide means for vertical movement relative thereto, said frame having upper and lower ends, a carriage supported on said frame for vertical movement over said frame, a drilling unit carried by said carriage, and elevating mechanism having a power unit coupled to both the frame and carriage, said elevating mechanism having means constructed and arranged to elevate the frame prior to upward movement of the carriage on the frame until the upper end of the frame engagesthe ceiling of the mine and for thereafter elevat-` ing the carriage relative to the frame while holding the frame in engagement against the ceiling, whereby initial` upward movement of the drilling unit is effected by elevation of said frame and subsequent upward movement eiected by elevation of the drilling unit over said frame,

the drilling unit being braced by. engagement of the frame with the ceiling of the mine during subsequent elevation.

References ted in the file 01EA this patent UNITED STATES PATENTS' 1,977,349 Nell Oct. 16, 1934 1,991,576 Remde Feb. 19, 1935 2,075,185 Eiler Mar. 30,1937' 2,079,189 Simpson et al. May 4, 1937 2,088,649 Hart Aug. 3, 1937' 2,149,348 Kelley Mar. 7; 1939 2,362,161 Sellars Nov. 7, 1944- 2,389,558 Slater Nov. 20,' 1945 2,480,066 Weaver Aug. 23', 1949" 2,590,958 Goodrich Apr. 1, 1952" 2,670,931 Curtis Mar. 2, 1954 2,718,118 Benjamin Sept. 20, 1955' 2,765,148 Prince Oct. 2, 1956 

